Initialization and manipulation of libinput contexts

Data Structures

struct  libinput
 A handle for accessing libinput. More...
 
struct  libinput_interface
 libinput does not open file descriptors to devices directly, instead open_restricted() and close_restricted() are called for each path that must be opened. More...
 

Typedefs

typedef void(* libinput_log_handler) (struct libinput *libinput, enum libinput_log_priority priority, const char *format, va_list args) LIBINPUT_ATTRIBUTE_PRINTF(3
 Log handler type for custom logging. More...
 
typedef void(*) voi libinput_log_set_handler) (struct libinput *libinput, libinput_log_handler log_handler)
 Set the context's log handler. More...
 

Enumerations

enum  libinput_log_priority { LIBINPUT_LOG_PRIORITY_DEBUG , LIBINPUT_LOG_PRIORITY_INFO , LIBINPUT_LOG_PRIORITY_ERROR }
 Log priority for internal logging messages. More...
 
enum  libinput_event_type {
  LIBINPUT_EVENT_NONE , LIBINPUT_EVENT_DEVICE_ADDED , LIBINPUT_EVENT_DEVICE_REMOVED , LIBINPUT_EVENT_KEYBOARD_KEY ,
  LIBINPUT_EVENT_POINTER_MOTION , LIBINPUT_EVENT_POINTER_MOTION_ABSOLUTE , LIBINPUT_EVENT_POINTER_BUTTON , LIBINPUT_EVENT_POINTER_AXIS ,
  LIBINPUT_EVENT_TOUCH_DOWN , LIBINPUT_EVENT_TOUCH_UP , LIBINPUT_EVENT_TOUCH_MOTION , LIBINPUT_EVENT_TOUCH_CANCEL ,
  LIBINPUT_EVENT_TOUCH_FRAME , LIBINPUT_EVENT_TABLET_TOOL_AXIS , LIBINPUT_EVENT_TABLET_TOOL_PROXIMITY , LIBINPUT_EVENT_TABLET_TOOL_TIP ,
  LIBINPUT_EVENT_TABLET_TOOL_BUTTON , LIBINPUT_EVENT_TABLET_PAD_BUTTON , LIBINPUT_EVENT_TABLET_PAD_RING , LIBINPUT_EVENT_TABLET_PAD_STRIP ,
  LIBINPUT_EVENT_TABLET_PAD_KEY , LIBINPUT_EVENT_GESTURE_SWIPE_BEGIN , LIBINPUT_EVENT_GESTURE_SWIPE_UPDATE , LIBINPUT_EVENT_GESTURE_SWIPE_END ,
  LIBINPUT_EVENT_GESTURE_PINCH_BEGIN , LIBINPUT_EVENT_GESTURE_PINCH_UPDATE , LIBINPUT_EVENT_GESTURE_PINCH_END , LIBINPUT_EVENT_SWITCH_TOGGLE
}
 Event type for events returned by libinput_get_event(). More...
 

Functions

struct libinputlibinput_udev_create_context (const struct libinput_interface *interface, void *user_data, struct udev *udev)
 Create a new libinput context from udev. More...
 
int libinput_udev_assign_seat (struct libinput *libinput, const char *seat_id)
 Assign a seat to this libinput context. More...
 
struct libinputlibinput_path_create_context (const struct libinput_interface *interface, void *user_data)
 Create a new libinput context that requires the caller to manually add or remove devices with libinput_path_add_device() and libinput_path_remove_device(). More...
 
struct libinput_devicelibinput_path_add_device (struct libinput *libinput, const char *path)
 Add a device to a libinput context initialized with libinput_path_create_context(). More...
 
void libinput_path_remove_device (struct libinput_device *device)
 Remove a device from a libinput context initialized with libinput_path_create_context() or added to such a context with libinput_path_add_device(). More...
 
int libinput_get_fd (struct libinput *libinput)
 libinput keeps a single file descriptor for all events. More...
 
int libinput_dispatch (struct libinput *libinput)
 Main event dispatchment function. More...
 
struct libinput_eventlibinput_get_event (struct libinput *libinput)
 Retrieve the next event from libinput's internal event queue. More...
 
enum libinput_event_type libinput_next_event_type (struct libinput *libinput)
 Return the type of the next event in the internal queue. More...
 
void libinput_set_user_data (struct libinput *libinput, void *user_data)
 Set caller-specific data associated with this context. More...
 
void * libinput_get_user_data (struct libinput *libinput)
 Get the caller-specific data associated with this context, if any. More...
 
int libinput_resume (struct libinput *libinput)
 Resume a suspended libinput context. More...
 
void libinput_suspend (struct libinput *libinput)
 Suspend monitoring for new devices and close existing devices. More...
 
struct libinputlibinput_ref (struct libinput *libinput)
 Add a reference to the context. More...
 
struct libinputlibinput_unref (struct libinput *libinput)
 Dereference the libinput context. More...
 
void libinput_log_set_priority (struct libinput *libinput, enum libinput_log_priority priority)
 Set the log priority for the libinput context. More...
 
enum libinput_log_priority libinput_log_get_priority (const struct libinput *libinput)
 Get the context's log priority. More...
 

Detailed Description

Typedef Documentation

◆ libinput_log_handler

typedef void(* libinput_log_handler) (struct libinput *libinput, enum libinput_log_priority priority, const char *format, va_list args) LIBINPUT_ATTRIBUTE_PRINTF(3

Log handler type for custom logging.

Parameters
libinputThe libinput context
priorityThe priority of the current message
formatMessage format in printf-style
argsMessage arguments
See also
libinput_log_set_priority
libinput_log_get_priority
libinput_log_set_handler

◆ libinput_log_set_handler

typedef void(*) voi libinput_log_set_handler) (struct libinput *libinput, libinput_log_handler log_handler)

Set the context's log handler.

Messages with priorities equal to or higher than the context's log priority will be passed to the given log handler.

The default log handler prints to stderr.

Parameters
libinputA previously initialized libinput context
log_handlerThe log handler for library messages.
See also
libinput_log_set_priority
libinput_log_get_priority

Enumeration Type Documentation

◆ libinput_event_type

Event type for events returned by libinput_get_event().

Enumerator
LIBINPUT_EVENT_NONE 

This is not a real event type, and is only used to tell the user that no new event is available in the queue.

See libinput_next_event_type().

LIBINPUT_EVENT_DEVICE_ADDED 

Signals that a device has been added to the context.

The device will not be read until the next time the user calls libinput_dispatch() and data is available.

This allows setting up initial device configuration before any events are created.

LIBINPUT_EVENT_DEVICE_REMOVED 

Signals that a device has been removed.

No more events from the associated device will be in the queue or be queued after this event.

LIBINPUT_EVENT_KEYBOARD_KEY 
LIBINPUT_EVENT_POINTER_MOTION 
LIBINPUT_EVENT_POINTER_MOTION_ABSOLUTE 
LIBINPUT_EVENT_POINTER_BUTTON 
LIBINPUT_EVENT_POINTER_AXIS 
LIBINPUT_EVENT_TOUCH_DOWN 
LIBINPUT_EVENT_TOUCH_UP 
LIBINPUT_EVENT_TOUCH_MOTION 
LIBINPUT_EVENT_TOUCH_CANCEL 
LIBINPUT_EVENT_TOUCH_FRAME 

Signals the end of a set of touchpoints at one device sample time.

This event has no coordinate information attached.

LIBINPUT_EVENT_TABLET_TOOL_AXIS 

One or more axes have changed state on a device with the LIBINPUT_DEVICE_CAP_TABLET_TOOL capability.

This event is only sent when the tool is in proximity, see LIBINPUT_EVENT_TABLET_TOOL_PROXIMITY for details.

The proximity event contains the initial state of the axis as the tool comes into proximity. An event of type LIBINPUT_EVENT_TABLET_TOOL_AXIS is only sent when an axis value changes from this initial state. It is possible for a tool to enter and leave proximity without sending an event of type LIBINPUT_EVENT_TABLET_TOOL_AXIS.

An event of type LIBINPUT_EVENT_TABLET_TOOL_AXIS is sent when the tip state does not change. See the documentation for LIBINPUT_EVENT_TABLET_TOOL_TIP for more details.

Since
1.2
LIBINPUT_EVENT_TABLET_TOOL_PROXIMITY 

Signals that a tool has come in or out of proximity of a device with the LIBINPUT_DEVICE_CAP_TABLET_TOOL capability.

Proximity events contain each of the current values for each axis, and these values may be extracted from them in the same way they are with LIBINPUT_EVENT_TABLET_TOOL_AXIS events.

Some tools may always be in proximity. For these tools, events of type LIBINPUT_TABLET_TOOL_PROXIMITY_STATE_IN are sent only once after LIBINPUT_EVENT_DEVICE_ADDED, and events of type LIBINPUT_TABLET_TOOL_PROXIMITY_STATE_OUT are sent only once before LIBINPUT_EVENT_DEVICE_REMOVED.

If the tool that comes into proximity supports x/y coordinates, libinput guarantees that both x and y are set in the proximity event.

When a tool goes out of proximity, the value of every axis should be assumed to have an undefined state and any buttons that are currently held down on the stylus are marked as released. Button release events for each button that was held down on the stylus are sent before the proximity out event.

Since
1.2
LIBINPUT_EVENT_TABLET_TOOL_TIP 

Signals that a tool has come in contact with the surface of a device with the LIBINPUT_DEVICE_CAP_TABLET_TOOL capability.

On devices without distance proximity detection, the LIBINPUT_EVENT_TABLET_TOOL_TIP is sent immediately after LIBINPUT_EVENT_TABLET_TOOL_PROXIMITY for the tip down event, and immediately before for the tip up event.

The decision when a tip touches the surface is device-dependent and may be derived from pressure data or other means. If the tip state is changed by axes changing state, the LIBINPUT_EVENT_TABLET_TOOL_TIP event includes the changed axes and no additional axis event is sent for this state change. In other words, a caller must look at both LIBINPUT_EVENT_TABLET_TOOL_AXIS and LIBINPUT_EVENT_TABLET_TOOL_TIP events to know the current state of the axes.

If a button state change occurs at the same time as a tip state change, the order of events is device-dependent.

Since
1.2
LIBINPUT_EVENT_TABLET_TOOL_BUTTON 

Signals that a tool has changed a logical button state on a device with the LIBINPUT_DEVICE_CAP_TABLET_TOOL capability.

Button state changes occur on their own and do not include axis state changes. If button and axis state changes occur within the same logical hardware event, the order of the LIBINPUT_EVENT_TABLET_TOOL_BUTTON and LIBINPUT_EVENT_TABLET_TOOL_AXIS event is device-specific.

This event is not to be confused with the button events emitted by the tablet pad. See LIBINPUT_EVENT_TABLET_PAD_BUTTON.

See also
LIBINPUT_EVENT_TABLET_PAD_BUTTON
Since
1.2
LIBINPUT_EVENT_TABLET_PAD_BUTTON 

A button pressed on a device with the LIBINPUT_DEVICE_CAP_TABLET_PAD capability.

A button differs from LIBINPUT_EVENT_TABLET_PAD_KEY in that buttons are sequentially indexed from 0 and do not carry any other information. Keys have a specific functionality assigned to them. The key code thus carries a semantic meaning, a button number does not.

This event is not to be confused with the button events emitted by tools on a tablet (LIBINPUT_EVENT_TABLET_TOOL_BUTTON).

Since
1.3
LIBINPUT_EVENT_TABLET_PAD_RING 

A status change on a tablet ring with the LIBINPUT_DEVICE_CAP_TABLET_PAD capability.

Since
1.3
LIBINPUT_EVENT_TABLET_PAD_STRIP 

A status change on a strip on a device with the LIBINPUT_DEVICE_CAP_TABLET_PAD capability.

Since
1.3
LIBINPUT_EVENT_TABLET_PAD_KEY 

A key pressed on a device with the LIBINPUT_DEVICE_CAP_TABLET_PAD capability.

A key differs from LIBINPUT_EVENT_TABLET_PAD_BUTTON in that keys have a specific functionality assigned to them (buttons are sequentially ordered). The key code thus carries a semantic meaning, a button number does not.

Since
1.15
LIBINPUT_EVENT_GESTURE_SWIPE_BEGIN 
LIBINPUT_EVENT_GESTURE_SWIPE_UPDATE 
LIBINPUT_EVENT_GESTURE_SWIPE_END 
LIBINPUT_EVENT_GESTURE_PINCH_BEGIN 
LIBINPUT_EVENT_GESTURE_PINCH_UPDATE 
LIBINPUT_EVENT_GESTURE_PINCH_END 
LIBINPUT_EVENT_SWITCH_TOGGLE 
Since
1.7

◆ libinput_log_priority

Log priority for internal logging messages.

Enumerator
LIBINPUT_LOG_PRIORITY_DEBUG 
LIBINPUT_LOG_PRIORITY_INFO 
LIBINPUT_LOG_PRIORITY_ERROR 

Function Documentation

◆ libinput_dispatch()

int libinput_dispatch ( struct libinput libinput)

Main event dispatchment function.

Reads events of the file descriptors and processes them internally. Use libinput_get_event() to retrieve the events.

Dispatching does not necessarily queue libinput events. This function should be called immediately once data is available on the file descriptor returned by libinput_get_fd(). libinput has a number of timing-sensitive features (e.g. tap-to-click), any delay in calling libinput_dispatch() may prevent these features from working correctly.

Parameters
libinputA previously initialized libinput context
Returns
0 on success, or a negative errno on failure

◆ libinput_get_event()

struct libinput_event* libinput_get_event ( struct libinput libinput)

Retrieve the next event from libinput's internal event queue.

After handling the retrieved event, the caller must destroy it using libinput_event_destroy().

Parameters
libinputA previously initialized libinput context
Returns
The next available event, or NULL if no event is available.

◆ libinput_get_fd()

int libinput_get_fd ( struct libinput libinput)

libinput keeps a single file descriptor for all events.

Call into libinput_dispatch() if any events become available on this fd.

Returns
The file descriptor used to notify of pending events.

◆ libinput_get_user_data()

void* libinput_get_user_data ( struct libinput libinput)

Get the caller-specific data associated with this context, if any.

Parameters
libinputA previously initialized libinput context
Returns
The caller-specific data previously assigned in libinput_set_user_data(), libinput_path_create_context() or libinput_udev_create_context().

◆ libinput_log_get_priority()

enum libinput_log_priority libinput_log_get_priority ( const struct libinput libinput)

Get the context's log priority.

Messages with priorities equal to or higher than the argument will be printed to the current log handler.

The default log priority is LIBINPUT_LOG_PRIORITY_ERROR.

Parameters
libinputA previously initialized libinput context
Returns
The minimum priority of log messages to print.
See also
libinput_log_set_handler
libinput_log_set_priority

◆ libinput_log_set_priority()

void libinput_log_set_priority ( struct libinput libinput,
enum libinput_log_priority  priority 
)

Set the log priority for the libinput context.

Messages with priorities equal to or higher than the argument will be printed to the context's log handler.

The default log priority is LIBINPUT_LOG_PRIORITY_ERROR.

Parameters
libinputA previously initialized libinput context
priorityThe minimum priority of log messages to print.
See also
libinput_log_set_handler
libinput_log_get_priority

◆ libinput_next_event_type()

enum libinput_event_type libinput_next_event_type ( struct libinput libinput)

Return the type of the next event in the internal queue.

This function does not pop the event off the queue and the next call to libinput_get_event() returns that event.

Parameters
libinputA previously initialized libinput context
Returns
The event type of the next available event or LIBINPUT_EVENT_NONE if no event is available.

◆ libinput_path_add_device()

struct libinput_device* libinput_path_add_device ( struct libinput libinput,
const char *  path 
)

Add a device to a libinput context initialized with libinput_path_create_context().

If successful, the device will be added to the internal list and re-opened on libinput_resume(). The device can be removed with libinput_path_remove_device().

If the device was successfully initialized, it is returned in the device argument. The lifetime of the returned device pointer is limited until the next libinput_dispatch(), use libinput_device_ref() to keep a permanent reference.

Parameters
libinputA previously initialized libinput context
pathPath to an input device
Returns
The newly initiated device on success, or NULL on failure.
Note
It is an application bug to call this function on a libinput context initialized with libinput_udev_create_context().

◆ libinput_path_create_context()

struct libinput* libinput_path_create_context ( const struct libinput_interface interface,
void *  user_data 
)

Create a new libinput context that requires the caller to manually add or remove devices with libinput_path_add_device() and libinput_path_remove_device().

The context is fully initialized but will not generate events until at least one device has been added.

The reference count of the context is initialized to 1. See libinput_unref.

Parameters
interfaceThe callback interface
user_dataCaller-specific data passed to the various callback interfaces.
Returns
An initialized, empty libinput context.

◆ libinput_path_remove_device()

void libinput_path_remove_device ( struct libinput_device device)

Remove a device from a libinput context initialized with libinput_path_create_context() or added to such a context with libinput_path_add_device().

Events already processed from this input device are kept in the queue, the LIBINPUT_EVENT_DEVICE_REMOVED event marks the end of events for this device.

If no matching device exists, this function does nothing.

Parameters
deviceA libinput device
Note
It is an application bug to call this function on a libinput context initialized with libinput_udev_create_context().

◆ libinput_ref()

struct libinput* libinput_ref ( struct libinput libinput)

Add a reference to the context.

A context is destroyed whenever the reference count reaches 0. See libinput_unref.

Parameters
libinputA previously initialized valid libinput context
Returns
The passed libinput context

◆ libinput_resume()

int libinput_resume ( struct libinput libinput)

Resume a suspended libinput context.

This re-enables device monitoring and adds existing devices.

Parameters
libinputA previously initialized libinput context
See also
libinput_suspend
Returns
0 on success or -1 on failure

◆ libinput_set_user_data()

void libinput_set_user_data ( struct libinput libinput,
void *  user_data 
)

Set caller-specific data associated with this context.

libinput does not manage, look at, or modify this data. The caller must ensure the data is valid.

Parameters
libinputA previously initialized libinput context
user_dataCaller-specific data passed to the various callback interfaces.

◆ libinput_suspend()

void libinput_suspend ( struct libinput libinput)

Suspend monitoring for new devices and close existing devices.

This all but terminates libinput but does keep the context valid to be resumed with libinput_resume().

Parameters
libinputA previously initialized libinput context

◆ libinput_udev_assign_seat()

int libinput_udev_assign_seat ( struct libinput libinput,
const char *  seat_id 
)

Assign a seat to this libinput context.

New devices or the removal of existing devices will appear as events during libinput_dispatch().

libinput_udev_assign_seat() succeeds even if no input devices are currently available on this seat, or if devices are available but fail to open in libinput_interface::open_restricted. Devices that do not have the minimum capabilities to be recognized as pointer, keyboard or touch device are ignored. Such devices and those that failed to open ignored until the next call to libinput_resume().

This function may only be called once per context.

Parameters
libinputA libinput context initialized with libinput_udev_create_context()
seat_idA seat identifier. This string must not be NULL.
Returns
0 on success or -1 on failure.

◆ libinput_udev_create_context()

struct libinput* libinput_udev_create_context ( const struct libinput_interface interface,
void *  user_data,
struct udev *  udev 
)

Create a new libinput context from udev.

This context is inactive until assigned a seat ID with libinput_udev_assign_seat().

Parameters
interfaceThe callback interface
user_dataCaller-specific data passed to the various callback interfaces.
udevAn already initialized udev context
Returns
An initialized, but inactive libinput context or NULL on error

◆ libinput_unref()

struct libinput* libinput_unref ( struct libinput libinput)

Dereference the libinput context.

After this, the context may have been destroyed, if the last reference was dereferenced. If so, the context is invalid and may not be interacted with.

Bug:
When the refcount reaches zero, libinput_unref() releases resources even if a caller still holds refcounted references to related resources (e.g. a libinput_device). When libinput_unref() returns NULL, the caller must consider any resources related to that context invalid. See https://bugs.freedesktop.org/show_bug.cgi?id=91872.

Example code:

li = libinput_path_create_context(&interface, NULL);
device = libinput_path_add_device(li, "/dev/input/event0");
// get extra reference to device
// refcount reaches 0, so *all* resources are cleaned up,
// including device
// INCORRECT: device has been cleaned up and must not be used
// li = libinput_device_get_context(device);
struct libinput * libinput_path_create_context(const struct libinput_interface *interface, void *user_data)
Create a new libinput context that requires the caller to manually add or remove devices with libinpu...
struct libinput * libinput_unref(struct libinput *libinput)
Dereference the libinput context.
struct libinput_device * libinput_path_add_device(struct libinput *libinput, const char *path)
Add a device to a libinput context initialized with libinput_path_create_context().
struct libinput_device * libinput_device_ref(struct libinput_device *device)
Increase the refcount of the input device.
Parameters
libinputA previously initialized libinput context
Returns
NULL if context was destroyed otherwise the passed context